Sydney has dry, mild and sunny March

Details

Mild, sunny month with slightly below average temperatures

Below average rainfall

Sunniest March on record, averaging 8.9 hours of sunshine per day

Rainfall

The total March rainfall of 63.4 mm at Sydney Observatory Hill was
well below the historic March average1 of 130 mm. There were 11 rain days
during the month, slightly below the March average of 13 rain days. Below average rainfall occurred over most of the metropolitan area but totals were closer to the average in the west and south where storms were more active. Totals ranged from 116 mm at Cronulla in the south to a low of only 28.0 mm at Avalon on Sydney's northern beaches.

The dry conditions in Sydney were caused mainly by a blocking high pressure system maintaining stable conditions over NSW for most of the month with most rain-bearing systems being directed SE away from the state.

The Warragamba Dam catchment recorded only light rain during March contributing to a slight fall in storage levels.
Monthly totals over the entire catchment were generally 20 - 50 mm. Recent rainfall in Sydney's drinking
water catchments can be found on the Sydney Catchment Authority web site http://www.sca.nsw.gov.au/dams/rainfall.html.

Temperatures

Average to slightly below average maximum temperatures were recorded over the Sydney metropolitan area during March. The average maximum temperature at Observatory Hill was 25.1°C, which
is slightly below the historic1 average maximum. Although maximum temperatures averaged a degree or two higher in the western suburbs, they were still close to or slightly below the normal for March.

As an indication of the mild conditions over the past 5 months, the maximum temperature in Sydney did not exceeded 31°C for the period 1 November 2007 to 31 March 2008. The last time Sydney experienced such conditions was back in 1872−73. Normally Sydney would expect 10 days over the 5 month period with temperatures exceeding 31°C.

Night-time temperatures were below the historic average over the whole Sydney metropolitan area during March. The average minimum temperature of 17.4°C at
Observatory Hill was 0.6°C below the historic1 March average. Clear skies and light winds contributed towards the below average night-time temperatures, especially in the west. The average minimum temperature at Richmond was 14.2°C, the coolest for March for 12 years.

The highest temperature at Sydney (Observatory Hill) during March was 28.1°C on the 20th while the lowest overnight temperature was 12.8°C on the 1st. Corresponding extremes in the Sydney metropolitan area ranged from a daytime high of 33.2°C at Penrith Lakes on the 20th to an overnight low of 5.9°C at Camden Airport on the 31st.

Wind

The prevailing direction over coastal Sydney during the afternoons was SE - NE for 70−80% of the time, which is above the normal frequency of 65% from this direction. The highest wind gust recorded was 74 km/hr at Sydney Airport on the 21st associated with a strong southerly change.

Other phenomena

Four thunderstorms were reported from the official Sydney city site during March, against an historic average of 2 storms. A severe storm on the 7th caused heavy rain in western and northern parts of Sydney with Berowra recording the highest metropolitan daily rainfall of 65 mm (to 9am 8th).

Generally cloudless skies prevailed in Sydney during March with the city experiencing its sunniest March on record. The average sunshine of 8.9 hours per day was well above the historic average of 6.8 hours per day. Previous sunniest March was 8.7 hours per day in 1981 (sunshine records date from 1912).

Notes

This statement has been prepared based on information available at
10 am on Tuesday 1 April 2008.
Some checks have been made on the data, but it is possible that results will change
as new information becomes available.

1Averages: historic average temperatures for
Observatory Hill and Richmond are based on the period 1961 to 1990 which is a convention of the World Meteorological Organisation.
Average temperatures for Parramatta are based on all available
data, 1968 - 2007 and Camden 1972 - 2007. Rainfall averages
and extremes for Observatory Hill are based on all years of record
1859 - 2007.

Normals are long-term means based on observations from
all available years of record, which vary widely from site to site.
They are not shown for sites with less than 10 years of record, as they cannot then be calculated reliably.
The median
is sometimes more representative than the
mean
of "normal" rain.

The Rank indicates how rainfall this time compares with the climate record for the site,
based on the
decile ranking
(very low rainfall is in decile 1, low in decile 2 or 3,
normal in decile 4 to 7, high in decile 8 or 9
and very high is in decile 10).
The Fraction of normal shows how much rain has fallen this time as a
percentage of the long-term mean.